<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Config
 * @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Json.php 24810 2012-05-17 21:20:12Z rob $
 */
/**
 *
 * @see Zend_Config
 */
require_once 'Zend/Config.php';
/**
 *
 * @see Zend_Json
 */
require_once 'Zend/Json.php';

/**
 * JSON Adapter for Zend_Config
 * @category Zend
 * @package Zend_Config
 * @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Config_Json extends Zend_Config {

    /**
     * Name of object key indicating section current section extends
     */
    const EXTENDS_NAME = "_extends";

    /**
     * Whether or not to ignore constants in the JSON string
     * Note: if you do not have constant names in quotations in your JSON
     * string, they may lead to syntax errors when parsing.
     * @var bool
     */
    protected $_ignoreConstants = false;

    /**
     * Whether to skip extends or not
     * @var boolean
     */
    protected $_skipExtends = false;

    /**
     * Loads the section $section from the config file encoded as JSON
     * Sections are defined as properties of the main object
     * In order to extend another section, a section defines the "_extends"
     * property having a value of the section name from which the extending
     * section inherits values.
     * Note that the keys in $section will override any keys of the same
     * name in the sections that have been included via "_extends".
     * @param string $json JSON file or string to process
     * @param mixed $section Section to process
     * @param boolean $options Whether modifiacations are allowed at runtime
     * @throws Zend_Config_Exception When JSON text is not set or cannot be loaded
     * @throws Zend_Config_Exception When section $sectionName cannot be found in $json
     */
    public function __construct ($json, $section = null, $options = false) {
        if (empty ($json)) {
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception ('Filename is not set');
        }
        $allowModifications = false;
        if (is_bool ($options)) {
            $allowModifications = $options;
        } elseif (is_array ($options)) {
            foreach ($options as $key => $value) {
                switch (strtolower ($key)) {
                    case 'allow_modifications' :
                    case 'allowmodifications' :
                        $allowModifications = (bool) $value;
                        break;
                    case 'skip_extends' :
                    case 'skipextends' :
                        $this -> _skipExtends = (bool) $value;
                        break;
                    case 'ignore_constants' :
                    case 'ignoreconstants' :
                        $this -> _ignoreConstants = (bool) $value;
                        break;
                    default :
                        break;
                }
            }
        }
        set_error_handler (array($this, '_loadFileErrorHandler')); // Warnings and errors are suppressed
        if ($json[0] != '{') {
            $json = file_get_contents ($json);
        }
        restore_error_handler ();
        // Check if there was a error while loading file
        if ($this -> _loadFileErrorStr !== null) {
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception ($this -> _loadFileErrorStr);
        }
        // Replace constants
        if ( ! $this -> _ignoreConstants) {
            $json = $this -> _replaceConstants ($json);
        }
        // Parse/decode
        $config = Zend_Json::decode ($json);
        if (null === $config) {
            // decode failed
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception ("Error parsing JSON data");
        }
        if ($section === null) {
            $dataArray = array();
            foreach ($config as $sectionName => $sectionData) {
                $dataArray[$sectionName] = $this -> _processExtends ($config, $sectionName);
            }
            parent::__construct ($dataArray, $allowModifications);
        } elseif (is_array ($section)) {
            $dataArray = array();
            foreach ($section as $sectionName) {
                if ( ! isset ($config[$sectionName])) {
                    require_once 'Zend/Config/Exception.php';
                    throw new Zend_Config_Exception (sprintf ('Section "%s" cannot be found', $sectionName));
                }
                $dataArray = array_merge ($this -> _processExtends ($config, $sectionName), $dataArray);
            }
            parent::__construct ($dataArray, $allowModifications);
        } else {
            if ( ! isset ($config[$section])) {
                require_once 'Zend/Config/Exception.php';
                throw new Zend_Config_Exception (sprintf ('Section "%s" cannot be found', $section));
            }
            $dataArray = $this -> _processExtends ($config, $section);
            if ( ! is_array ($dataArray)) {
                // Section in the JSON data contains just one top level string
                $dataArray = array($section => $dataArray);
            }
            parent::__construct ($dataArray, $allowModifications);
        }
        $this -> _loadedSection = $section;
    }

    /**
     * Helper function to process each element in the section and handle
     * the "_extends" inheritance attribute.
     * @param array $data Data array to process
     * @param string $section Section to process
     * @param array $config Configuration which was parsed yet
     * @throws Zend_Config_Exception When $section cannot be found
     * @return array
     */
    protected function _processExtends (array $data, $section, array $config = array()) {
        if ( ! isset ($data[$section])) {
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception (sprintf ('Section "%s" cannot be found', $section));
        }
        $thisSection = $data[$section];
        if (is_array ($thisSection) && isset ($thisSection[self::EXTENDS_NAME])) {
            if (is_array ($thisSection[self::EXTENDS_NAME])) {
                require_once 'Zend/Config/Exception.php';
                throw new Zend_Config_Exception ('Invalid extends clause: must be a string; array received');
            }
            $this -> _assertValidExtend ($section, $thisSection[self::EXTENDS_NAME]);
            if ( ! $this -> _skipExtends) {
                $config = $this -> _processExtends ($data, $thisSection[self::EXTENDS_NAME], $config);
            }
            unset ($thisSection[self::EXTENDS_NAME]);
        }
        $config = $this -> _arrayMergeRecursive ($config, $thisSection);
        return $config;
    }

    /**
     * Replace any constants referenced in a string with their values
     * @param string $value
     * @return string
     */
    protected function _replaceConstants ($value) {
        foreach ($this -> _getConstants () as $constant) {
            if (strstr ($value, $constant)) {
                // handle backslashes that may represent windows path names for instance
                $replacement = str_replace ('\\', '\\\\', constant ($constant));
                $value = str_replace ($constant, $replacement, $value);
            }
        }
        return $value;
    }

    /**
     * Get (reverse) sorted list of defined constant names
     * @return array
     */
    protected function _getConstants () {
        $constants = array_keys (get_defined_constants ());
        rsort ($constants, SORT_STRING);
        return $constants;
    }

}
